For sure wood chopping is a good workout. In winter here in the US I have various places where I'll go to help chop wood. I some family members with a great deal of forest and they have stock piles of wood used to heat wood burning stoves. FYI noting beats a wood burning stove. When I help out it's not intended to be exercise, but after a good hour or two chopping wood (not to mention hauling it) I'm not thinking about a workout. I think it's definitely a combination of both, but I'd say more anaerobic because (at least for me I'm chopping up a whole tree) you'll have a few forceful bouts with little periods of rest over a long period of time.

I have a small wood burning fireplace in my home and I couldn't live without it. The smell of the woodsmoke, the feel of the natural heat on my face, the color and light of it in the evening--you can't top real, live flames! It's nice to know that even if the power goes out, I'm going to be comfortable in the wintertime; I always keep two days worth of wood stacked up in storage for just that and it's all cedar (Oh, baby!) I admit that I cheat and use a circular saw to section off pieces but it's an old saw, weighs a ton in my hand, and I do it hunched over on the floor of my garage, so I'll give myself a half-point for that. I've actually always wanted to learn to wield a full-sized ax with precision. It truly is a composite workout.